Technical Field
The present invention relates to an optical image capturing lenses. More particularly, the present invention relates to a compact optical image capturing lenses applicable to electronic products.
Description of Related Art
In recent years, with the popularity of mobile products with camera functionalities, the demand for miniaturizing an optical image capturing lenses is increasing. The sensor of a conventional photographing camera is typically a CCD (Charge Coupled Device) or a CMOS (Complementary Metal-Oxide 2o Semiconductor Sensor). As advanced semiconductor manufacturing technologies have allowed the pixel size of sensors to be reduced and compact optical image capturing lenses have gradually evolved toward the fields of higher megapixels, there is an increasing demand for optical image capturing lenses featuring better image quality.
A conventional optical image capturing lenses in a portable electronic product typically utilizes a three-element lens structure. Such a conventional optical image capturing lenses has a first lens element with positive refractive power, a second lens element with negative refractive power and a third lens element with positive refractive power. The first, second and third lens elements are arranged in this order from an object-side to an mage-side. Although the three-element lens structure is compact, it not able to produce high quality images.
Further, another conventional compact optical image capturing lenses provides a four-element lens structure. The first lens element and the second lens element of the four-element lens structure are two glass spherical lens elements which are attached to each other to form a doublet lens for eliminating chromatic aberration. However, this lens structure requires a longer total optical track length caused by insufficient degrees of freedom in setting system parameters due to too many spherical lenses allocated. Moreover, it is not easy to attach the glass lenses, and thus the manufacturing process for forming the glass doublet lenses is difficult. Therefore, a need exists in the art for providing an optical image capturing lenses for use in a mobile electronic product that has excellent imaging quality without too long total track length. Moreover, the problem of the foregoing optical image capturing lenses is that both of the image quality and the production cost can not be maintained. In detail, two different lenses assemblies should be used when photographing a near object and a far object. However, the difficulty or the cost of the production would be increased by preparing two lenses assemblies or one lenses assembly which can be adjusted.